Ethyleneamine polyphosphates as described in U.S. Pat. No. 7,138,443 and US patent application 20090048372 are effective environmentally friendly halogen free flame retardants. However ethyleneamine polyphosphate has some deficiencies in practical use. (1) Preparation of ethyleneamine polyphosphate is inefficient. The process in U.S. Pat. No. 7,138,443 and US patent application 20090048372 has less than an 85% yield, resulting in a 15% non viscous phase or more. The non viscous phase has a high phosphorous content and many publically operated treatment facilities (POT) cannot accept such a non viscous phase leading to a costly disposal problem. (3) TGA indicates that ethyleneamine polyphosphates made according to U.S. Pat. No. 7,138,443 start to decompose at a temperature of 300° C., which will cause problems in extrusion when such temperatures are reached. (4) The efficiency of flame retardants of U.S. Pat. No. 7,138,443 would be more efficient if they decomposed at temperatures above 350 C to be closer to decomposition temperature of polymers. (5) Polymers containing ethyleneamine polyphosphates sag or drip when exposed to a flame in the UL94 test. (6) It is difficult to load more than about 25% of ethyleneamine polyphosphates into polymers such as polypropylene and a compatibilizer is needed for high loadings. (7) In US patent application 20090048372, ethyleneamine polyphosphates are claimed with stability better than 1.5% at 315° C.
The flame retardants of this invention helps to greatly reduce the problems of dripping and/or sagging of polymeric compositions containing ethyleneamine polyphosphate in a flame. Finally, a new ethyleneamine polyphosphate is invented that is at least 45° C. more stable than the standard ethyleneamine polyphosphate of U.S. Pat. No. 7,138,443 and the new process has better than 95% yield and utilizes the non viscous phase of U.S. Pat. No. 7,138,443. A compatibilizer is also defined.